In the Interest of Vengeance
by sekdaniels
Summary: First Year's practice simple spells for weeks before mastering them, but Harry Potter managed to whip out Sectumsempra on his first go? Highly unlikely. An exploration of how he might've geared up for that fateful altercation with Draco, and how it might *not* have gone unnoticed by a certain Professor who knew it all too well. Trigger warning: implied violence, blood


**A/N:** another entry to TGS Sing-A-Song Along challenge for the wonderful Jenny! Happy birthday.

 **In the Interest of Vengeance**

He knew there was something off about it. The damage to the Whomping Willow was far too symmetrical; far to regular to have been a lightning strike. Precise diagonals cut across the bark, spaced in such a way that it could have been a swipe from an overly large animal with proportionally sized claws.

Severus ran his hands over the gouges. They were deep, but smooth. And he had no idea what had caused them, but something about these particular marks were troublesome.

He tended to the tree, as was his want. Pomona was most oft associated with all things magically grown, but the fact was any student of Potions had best have a bit of green thumb as well. And to be a Potions _Master_ would require more than a bit; what could not be easily foraged or purchased would need to be grown. As his skills with potions developed, Severus found he was also exceptional at growing things, even when thought to be past saving. The willow was one such reclamation, and Severus went out of his way to continue to care for the misunderstood tree.

This set of wounds, like the many others wrought by wild things roaming the forest or from the wrath of a stormy sky, would heal. And they did. And it was forgotten.

Until a similar set of marks showed up not a few weeks later, this time tucked away on an otherwise unobserved wall of stone near the Boat House. Strong, deep striations, again, on a diagonal, is if a huge paw of sharp claws had struck out in haste. Severus himself hardly noticed it except that he had found himself pacing most of the night away, and was still in the more remote part of the castle come daybreak. His walk back to his quarters was disturbed by the odd glint of light that caught his attention in the rising sun. As he ran his hands over the gashes, he could see the twinkle of bare quartz, newly exposed, shine and glitter in the growing daylight.

In the bark of the tree, it was not as noticable; but here, the cuts were crystal clear and easy to read. He knew what they were. His own handiwork, of a sort.

 _Sectumsepra_.

The night's worries were washed away in an instant of panic as he strode swiftly towards the castle. Someone had discovered his spell. Someone who planned to use it.

 _Like I had. To defend myself; to prove myself._

His immediate impulse was to was to demand a meeting of all Heads of House in Headmaster's office; but, as he flew down the still empty corridors, his robes snapping and swirling, he remembered. Dumbledore was off on another mission. Something secret; something vital.

He would either have to count on Minerva to support him or go it alone.

He knew the choice was already made.

Difficult as it was, he jumped to no conclusions. Severus no longer ruled Potions; that was left to the skilled, but mostly unobservant Professor Slughorn. Severus cornered him several times inquiring about "unusual behavior" or "an odd amount of success in unexpected places" only to be met with a petrified stare down his bulbous, sweaty nose, and barely of stuttered answer from Horace. _He_ would be of no help.

As the weeks and months passed, Severus reflected on the marking he had last seen. No others had been recorded, and he could see why. They spell was almost perfectly executed. Had a human body been standing there instead of a stone wall, it would've been shredded to bits. He had to assume the one responsible knew it as well, and knocked off with "practice". This worried Severus all the more since it meant the next time he was like to see the spell, it would be on flesh and bone.

When the time came, he never said a word to the boy. He didn't have time. Severus sent up a silent prayer and bent to the task of knitting Malfoy back together. Undoing the handy work of his own spell was a bitter task, but knowing who had executed it was nastier still. All his work and sacrifice to protect the boy, _her boy_ —for what? So he could go about starting a war no one was ready for single-handed?

He stood, soaked to the skin in the devastated bathroom and allowed the tears to spill. No one would see them amongst the spraying water of broken pipes. He tried so hard to remember _her_ —but that boy insisted on reminding him, constantly, that he was James Potter's son, too.

And it killed him.


End file.
